Although the review extract included on the dustwrapper is credited to The Guardian, it is actually from The Manchester Guardian - from a review of The Fellowship of the Ring in the 20 August 1954 issue.

...To have created so enthralling an epic- romance, with its own mythology, with such diversity of scene and character, such imaginative largesse in invention and description, and such supernatural meaning underlying the wealth of incident, is a most remarkable feat. Mr Tolkien is one of those born story-tellers who makes his readers as eager as wide-eyed children for more. His style, in prose and verse, is fresh and fluent, and equally apt to the expression of unearthly beauty, homely humour or stark horror.'